GARBONATE OF LIME. 
The most vital fact is one that we cannot now ex- 
.plain: the carbonate of lime makes the nitrifying 
bacteria thrive. They cannot seem to exist with- 
out it. Then it keeps the alfalfa in good health. 
Why should alfalfa or any other plant become sick? 
We think we know that plants give off certain toxic 
principles, poisonous to themselves. That is, the 
alfalfa roots exhale perhaps a poison that is in- 
jurious to itself and to other alfalfa roots. When 
there is much carbonate of lime in the soil this 
poisonous principle is in some way neutralized. Thus 
the alfalfa keeps in health and vigor and goes right 
on performing its miracles. This helps explain 
some things that have puzzled the wisest of us. 
Many men have had good, vigorous stands of alfalfa 
well fed with mineral fertilizers and with stable 
manures, and all at once with no warning whatever 
it would all die as though stricken with plague. This 
has happened repeatedly in many eastern and south- 
ern states. Never, so far as the writer has been able 
to learn, has it happened where the alfalfa was 
growing on a soil even fairly well supplied with 
carbonate of lime. 
Carbonate of lime, we may as well fairly confess, 
is ‘the very keynote of successful alfalfa culture. 
Drainage and carbonate of lime are the two essen- 
(107) 
